BIO CHAPTERS 1-10.1 definitions

Diffusion

The net movement of particles from a region of higher concentration to a region of lower concentration,down a concentration gradient

Osmosis

The net movement of water molecules from a region of higher water potential to a region with a lower water potential through a partially permeable membrane\

Active transport

The movement of particles from a reegion of lower concentration to a region of higher concentration, across a partially permeable membrane which requires energy from respiration

Enzymes

are proteins that function as biological catalysts. They catalyse or speed up the rate of chemical reactions by lowering the activation energy.They remain chemically unchanged at the end of the reaction

Nutrition

is the process by which organisms obtain food and energy for growth, repair and maintenance of the body. It involves the processes of ingestion,digestion,absorptio,assimilation and egestion

Ingestion

the intake of food through the mouth into the body

Peristalsis

is the rhythmic wave like alternate contraction and relaxation of longitudinal and circular muscles in the wall of the alimentary canal, to move food along.

Digestion

the breakdown of large,complex,insoluble food molecules into small,simple,soluble molecules to be absorbed into body cells

Absorption

the process where by digested food substances are transported from the small intesetine into the blood stream or lacteal

Assimilation

the process whereby some of the absorbed nutrients are converted into new cytoplasm of used to prvoide energy for the cells

Homeostasis

the maintenance of a constant internal environment

Osmoregulation

is the control of water potential and solute concentration level in the blood to maintain a constant water potential in the body

Hormones

Hormones are chemical substances produced in minute quantities by endocrine glands. They are transported by blood to one more specific target organs where its effects are exerted